Four solutions, namely fructose, ethanol, hydrochloric acid and sodium hydroxide filled in four separate beak…

Question

Four solutions, namely fructose, ethanol, hydrochloric acid and sodium hydroxide filled in four separate beakers are connected one by one in an electric circuit with a bulb. The solutions in which the bulb will glow when current is passed are :

Accepted Answer

## Model Answer **(D) hydrochloric acid and sodium hydroxide** HCl and NaOH ionize in water to produce H⁺ and OH⁻ ions respectively, allowing current to flow and the bulb to glow. Fructose and ethanol do not ionize, so they do not conduct electricity. Source: Chapter 2, Section 2.2 ## Explanation The key concept is ionic conduction: only solutions that produce free ions conduct electricity. Acids produce H⁺(aq) and bases produce OH⁻(aq) — both allow current flow. Non-electrolytes like fructose (sugar) and ethanol have no ions in solution, so the bulb stays off. Examiners expect you to identify the two ionic solutions correctly.

Science — CBSE Class 10 board question